Perspreview of the exposition 50 year at the Royal Palace in Amsterdam, on April 28, 2017, its open for free on Friday evening 28 April 2017 from 22.00, 50 hours in the context of King Willem-Alexander's 50th birthday with a selection of objects, including objects of the King Photo : Albert Nieboer / Netherlands OUT / Point de Vue OUT - NO WIRE SERVICE- Photo: Albert Nieboer/RoyalPress/dpa /MediaPunch ***FOR USA ONLY***